Rising air temperatures are linked to cognitive decline: How extreme heat affects our brain health
The scorching July summer of 2023 saw record heat in Phoenix and several other cities. While many of us complain of discomfort, a recent study has shed light on the far-reaching effects of extreme temperatures, particularly on cognitive health.
Extreme heat has long been recognized as the leading cause of weather-related deaths in the United States, surpassing hurricanes, tornadoes, and lightning strikes. However, the cognitive effects of extreme heat have only recently begun to attract attention. Previous studies have hinted at the negative effects of high temperatures on cognitive function, but most have focused on short-term effects, leaving long-term effects largely unexplored.
Eun Young Choi, a postdoctoral fellow at New York University’s School of Global Public Health, explains, “Our study shows that cumulative exposure to extreme heat can undermine cognitive health, but does so unevenly across different populations.” The study shows that repeated or prolonged exposure to extreme heat can have a detrimental effect on cognitive function. It triggers a cascade of events in the brain, including cell damage, inflammation and oxidative stress, which can deplete a person’s cognitive reserve.
The study, led by Virginia Chang, analyzed data from the University of Michigan Health and Retirement Study. The study lasted 12 years and involved about 9,500 U.S. adults aged 52 and older. Participants’ cognitive function was measured over time, and their cumulative exposure to extreme heat was determined using historical temperature records from the CDC’s National Environmental Health Tracking Network.
The findings were striking. High exposure to extreme heat was associated with faster cognitive decline in residents of poor neighborhoods. On the other hand, residents of affluent neighborhoods appeared to be more protected. Haena Lee, one of the study’s first authors, explains that affluent neighborhoods often have resources such as well-maintained green spaces, air conditioning and cooling centers that can help mitigate the effects of heat waves. Disadvantaged neighborhoods may lack these resources, making residents more vulnerable to cognitive decline.
The projected increase in the number of extremely hot days is a growing concern for residents. While the negative effects of extreme heat on mortality and physical health are well documented, the long-term effects on cognitive function at the end of life have yet to receive adequate attention. This study highlights the need for further research and targeted interventions to address the uneven effects of extreme heat on cognitive health.
Quoting scientists and experts:
– Eun Young Choi, a postdoctoral fellow at New York University’s School of Global Public Health: “Our study shows that cumulative exposure to extreme heat can undermine cognitive health, but does so unevenly across populations.”
– Virginia Chang, senior author of the study, “Cognitive decline may not be immediately apparent after a single exposure to heat, but repeated or prolonged exposure to extreme heat can be devastating.”
– Haena Lee, co-author of the study, “Affluent areas tend to have resources that can help during heat waves – such as well-maintained green spaces, air conditioning and cooling centers. Disadvantaged neighborhoods may not have these resources.”
